The present invention relates to a new and improved apparatus for guiding a ram in the machine frame of a punch press or stamping press or the like --hereinafter generally referred to as a punch press--, said apparatus being of the type comprising four guides arranged at least approximately in the corners of a rectangle, each guide possessing a guide column.
Modern punch presses or stamping machines operate with a high number of strokes, and thus due to the increased frictional losses causes an increase in the temperature of the punch press or the like. Moreover, for such type punch presses there are needed larger clamping surfaces or mounting tables for the tools, requiring large spacing between the guide columns of the ram. Both of the aforementioned factors render more difficult or impossible the desired accurate guiding of the ram during all operating conditions.
In order to permit free expansion of the ram during fluctuations in temperature, there have already been proposed to the art apparatus of the previously mentioned type wherein the ram is guided along a diagonally extending guide surface at each guide column. In the presence of lateral pressure in the lengthwise direction or the transverse direction of the ram, as such occurs during eccentric loading of the ram, only two out of the total of four guide locations or guides are loaded, which, owing to the unavoidable elastic deformations occurring at both of the non-loaded guides, produces play and thus inaccurate positioning of the ram.